Dental instrument.



No. 827,567. PATENTED'JULY 31, 1 906.

L. H. CRAWFORD.

DENTAL INSTRUMENT. APPLICATION rum) NOV.18, 190a. mmnwn n JAN. 6, 1906.

INVENTOf? @Mwzyfiae ATTORNEYS UNITED STATES PATENT OFFICE.

LYTER H. CRAWFORD, OF PHILADELPHIA, PENNSYLVANIA.

DENTAL INSTRUMENT.

Specification of Letters Patent.

PatentedJilly 3 1, 1906:

A li tio filed November 8, 1903. Renewed January 6. 1906. Serial No. 2946,919l

is a specification.

The object of my invention is to provide for the dental profession an improved substitute for the forceps for use in elevating and extracting roots of teeth. The construction and manner of using the same are as hereinafter described and illustrated in accompanying drawings, in which Figure l is a side view of my improved instrument. Fig. 2 is a plan view of the same. Fig. 3 is a longitudinal section of the handle and handle-section attached thereto. Fig. 4includes a plan end and side view of the elevator proper. Fig. 5 is an enlarged crosssection on the line 5 5 of Fig. 3. Figs. 6 and 7 are perspective views illustrating the prac tical use of the invention.

Referring in the first instance to the instrument as shown in Figs. 1 to 6, A indicates the elevator proper, B the handle-section to which it is attached, and C the handle proper. The handle C is recessed or bored at one end to receive a bushing or sleeve 1, which is threaded interiorly to receive the correspondinglythreaded portion of the handle-section B. The outer end of the handle-section B is provided with a longitudinal slot 2 (see Fig. 2) and with hooks 3, which are adapted to engage trunnions or pivots 4, formed on the flat shank of the elevator A. The inner or rear end 5 of said shank is formed upon the arc of a circle and serrated, as shown in Figs. 3 and 4.. The handle-section B is provided with a longitudinal bore, in which slides a rod 6, whose outer end is serrated corresponding to the shank of the elevator with which it is adapted to engage as shown. The rear portion of the bore in the handle-section B is enlarged sufliciently to receive a spiral spring 7, which encircles the locking rod or bolt 6 and is compressed between the head 8 of the latter and the shoulder 9 of the enlarged bore. The head 8 of the bolt 6 works in contact with the inner end of the bore in the handle 0 or with a hariilened piece of metal inserted therein. The handle-section B being screwed into the threaded bushing 1, itis apparent that by rotating it the bolt 6 may be-forced'out, so as to engage and lock the elevator. A, as

shown in Figs. 1, 2, or pressure on-the-bolt' ,may be released, when-the spring7 will-drawv the bolt out of engagement with the elevator,

thus allowingthe latter; to beset andlocked at any desiredangle to the handle andhandle section which conditions may require. It

is also apparent that by releasingthe tension on the spring 7 the elevator A may be readily. removedfrom the hooks 3 andia-nother one substituted, according to the requirements of the case.

The elevator is peculiarly constructed that is to say, in its main formor chiefcliaracteristic of shape, which isrightangularthe beak or working endlO beingcurved'and taperedand slightly concave-on one side and prominently convex onthe other.v Theelevator is further distinguished by a lateral curve, so that the'beak 10is set laterally or at an angle to the axis of the shank,.as-illustrated in Figs. 2 and 4'. It will be understood that this lateral deflection willbeto the right or left, accordingas a particular elevator has to be used on one side of. the mouthorv the other. In practical use of the instrument the point of the beak 10 is forced down between the tooth-root m which is to be extracted and the alveolar process, as crudely illustrated in Fig. 6, the convexity 11 of the beak bearing against an adjacent toothsay a molar yand constituting a point of leverage for the instrument as a whole. Then upon bearing upward a sufficient leverage is applied to the point of the beak 10 to loosen and disengage the tooth-root as, as will be readily understood.

It will be understood thatthe convexity 11 of the beak of the elevator will be anterior or posterior, as illustrated, respectively, by Figs.

'6 and 7, according to conditions-that is to say, according to the location of the toothroot which is .to be extracted. Thus in Fig. 7 the beak 10 is provided with a convexity 11 on the rear side, so that it is adapted to act against a root adjacent or near to a sound tooth located in front of it. Thus a series of elevators will be provided for each handle to form a complete instrument. It is unnecessary to describe further the details of construction and operation, since these will be readily understood by those skilled in the art. It is apparent that the instrument afiords an forming the terminal of the downward bend,

and ta eredj as'specified.

3. The improved surgical instrument for dental use, comprising a handle and a toothrootelevator having a beak arranged substantially ata right'angle to the shank, which is also 'curve'dlater'ally, the beak being ta-' pered to a point and made concavo-convex, the convexity being on the side which is farthest from the shank and the inner side being arranged practically at a right angle to the straight portion of the'shank, whereby the beak is adapted for insertion and leverage in the manner described.

4. The combination, with a handle and a handle-section adapted for adjustment longitudinally with reference to the latter, of the pivoted tooth-elevator, and means for looking the same at different angles, which consist of a sliding bolt whose head works in contact with the end of the bore in the handle, and a spiral spring surrounding the bolt and exerting pressure upon the same outwardly, substantially as described.

ably, and means for locking the elevator-inv rigid engagement with the hooks, substantially as described.

7. The combination, with the handle ing an engaging device at its free end, of the tooth-elevator proper which is pivotally con nected with said device and detachablethttrefrom, the shank of the elevator being con-- structed at its inner end upon the arc of a circle and serrated, and a locking device arranged in the handle and adapted to engage the serrations of the elevator-shank, substantially as described.

8. The combination, with the handle hav ing an engaging device at its outer end, of the tooth-elevator which is pivotally and detach ably connected with said device, and means for locking the elevator at any required angle and permitting the detachment of the same, substantially as described.

LYTER H. CRAWFORD.

Witnesses:

ANNA GEAR, WM. LANIER GAULBERT. 

